do you have a diagnosis for kylie? >> no. but we have a few good leads. >> reporter: for a time they suspected a rare brain disorder called epilepsy parshialis. it affects the brain's motor strength. but electrical charges in kylie's brain were not coming from just one area but in fact from all over. so they were back to square one. >> you try to differentiate whether this is something that was genetic or something environmental. in other words, that happened to her. really that's the dichotomy here. >> reporter: in time, an analysis of kylie's dna revealed the genetic clue. they found a mutation in a particular gene that makes a protein called laforin. is it possible what we're talking about here in regard to kylie is something that was never described before? >> it's very possible. >> reporter: brand-new. >> brand-new mutation, and maybe identifying a gene that is -- is not known previously to cause a human disease. >> reporter: back home in reno, nevada, gina and steven are trying to focus on enjoying the time they have as